Pre-adolescent children in three age groups, males (7-8 years N = 26; 9-10 years N = 58; 11-12 years N = 20) and females (7-8 years N = 28; 9-10 years N = 50; 11-12 years N = 20) were examined on a battery of anatomical and physiological tests. There were no significant interactions between age, sex, and sporting involvement. Differences between the sexes were independent of age and the sporting group.

Males were found to be superior to females in physical work capacity as revealed by the PWC170, forced vital capacity, and hand-grip strength tests. In terms of anthropometry, males demonstrated a lesser proportion of body fat than females and were more mesomorphic. No significant differences existed in measures of strength, power, and speed.

Implication. Pre-pubertal boys and girls are sufficiently similar in physical characteristics that there is no performance or structural reason why they should not be able to compete together. However, because of the lung-function differences males might have a slight advantage over females in endurance activities.